source/blender/io/usd/CMakeLists.txt

@@ -209,6 +209,10 @@ if(WITH_OPENVDB)
   )
 endif()
 
+if(WITH_MATERIALX)
+  list(APPEND LIB MaterialXCore)
+endif()
+
 blender_add_lib(bf_usd "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")
 
 # RNA_prototypes.h

source/blender/io/usd/hydra/hydra_scene_delegate.h

@@ -52,7 +52,9 @@ class HydraSceneDelegate : public pxr::HdSceneDelegate {
   const View3D *view3d = nullptr;
   Main *bmain = nullptr;
   Scene *scene = nullptr;
+
   ShadingSettings shading_settings;
+  bool use_materialx = true;
 
  private:
   ObjectDataMap objects_;

source/blender/io/usd/hydra/material.cc

@@ -12,6 +12,9 @@
 #include <pxr/imaging/hd/tokens.h>
 #include <pxr/usdImaging/usdImaging/materialParamUtils.h>
 
+#include <pxr/usd/usdMtlx/reader.h>
+#include <pxr/usd/usdMtlx/utils.h>
+
 #include "MEM_guardedalloc.h"
 
 #include "BKE_lib_id.h"
@@ -30,6 +33,7 @@
 
 #include "intern/usd_exporter_context.h"
 #include "intern/usd_writer_material.h"
+#include "shader/materialx/material.h"
 
 namespace blender::io::hydra {
 
@@ -66,10 +70,22 @@ void MaterialData::init()
                                          time,
                                          export_params,
                                          image_cache_file_path()};
-
   /* Create USD material. */
-  pxr::UsdShadeMaterial usd_material = usd::create_usd_material(
-      export_context, material_path, (Material *)id, "st");
+  pxr::UsdShadeMaterial usd_material;
+  if (scene_delegate_->use_materialx) {
+    MaterialX::DocumentPtr doc = blender::nodes::materialx::export_to_materialx(
+        scene_delegate_->depsgraph, (Material *)id);
+    pxr::UsdMtlxRead(doc, stage);
+    if (pxr::UsdPrim materials = stage->GetPrimAtPath(pxr::SdfPath("/MaterialX/Materials"))) {
+      pxr::UsdPrimSiblingRange children = materials.GetChildren();
+      if (!children.empty()) {
+        usd_material = pxr::UsdShadeMaterial(*children.begin());
+      }
+    }
+  }
+  else {
+    usd_material = usd::create_usd_material(export_context, material_path, (Material *)id, "st");
+  }
 
   /* Convert USD material to Hydra material network map, adapted for render delegate. */
   const pxr::HdRenderDelegate *render_delegate =

source/blender/nodes/shader/CMakeLists.txt

@@ -145,18 +145,19 @@ set(LIB
 
 if(WITH_MATERIALX)
   list(APPEND LIB MaterialXCore)
+  list(APPEND LIB MaterialXFormat)
   list(APPEND SRC
     materialx/material.cc
-    materialx/nodes/node.cc
-    materialx/nodes/material_output.cc
-    materialx/nodes/principled_bsdf.cc
-    materialx/nodes/image.cc
+    materialx/nodes/bsdf_principled.cc
+    materialx/nodes/node_parser.cc
+    materialx/nodes/output_material.cc
+    materialx/nodes/tex_image.cc
 
     materialx/material.h
-    materialx/nodes/node.h
-    materialx/nodes/material_output.h
-    materialx/nodes/principled_bsdf.h
-    materialx/nodes/image.h
+    materialx/nodes/bsdf_principled.h
+    materialx/nodes/node_parser.h
+    materialx/nodes/output_material.h
+    materialx/nodes/tex_image.h
   )
 endif()
 

source/blender/nodes/shader/materialx/material.cc

@@ -3,34 +3,37 @@
  * SPDX-License-Identifier: GPL-2.0-or-later */
 
 #include "material.h"
-#include "nodes/material_output.h"
+#include "nodes/output_material.h"
 
 #include <MaterialXCore/Node.h>
+#include <MaterialXFormat/XmlIo.h>
 
 #include "NOD_shader.h"
 
 namespace blender::nodes::materialx {
 
-static void export_nodegraph(MaterialX::DocumentPtr doc, Depsgraph *depsgraph, Material *material)
+static void export_nodegraph(MaterialX::GraphElement *graph,
+                             Depsgraph *depsgraph,
+                             Material *material)
 {
   material->nodetree->ensure_topology_cache();
 
   bNode *output_node = ntreeShaderOutputNode(material->nodetree, SHD_OUTPUT_ALL);
-  MaterialXMaterialOutputNode material_node(doc, depsgraph, material, output_node);
-  material_node.convert();
+  OutputMaterialNodeParser parser(graph, depsgraph, material, output_node);
+  parser.compute();
 }
 
-static void create_standard_surface(MaterialX::DocumentPtr doc, Material *material)
+static void create_standard_surface(MaterialX::GraphElement *graph, Material *material)
 {
-  MaterialX::NodePtr surfacematerial = doc->addNode(
-      "surfacematerial", MaterialX::EMPTY_STRING, "material");
-  MaterialX::NodePtr standard_surface = doc->addNode(
+  MaterialX::NodePtr standard_surface = graph->addNode(
       "standard_surface", MaterialX::EMPTY_STRING, "surfaceshader");
 
   standard_surface->addInput("base", "float")->setValue(1.0);
   standard_surface->addInput("base_color", "color3")
       ->setValue(MaterialX::Color3(material->r, material->g, material->b));
 
+  MaterialX::NodePtr surfacematerial = graph->addNode(
+      "surfacematerial", MaterialX::EMPTY_STRING, "material");
   surfacematerial->addInput(standard_surface->getType(), standard_surface->getType())
       ->setNodeName(standard_surface->getName());
 }
@@ -39,11 +42,13 @@ MaterialX::DocumentPtr export_to_materialx(Depsgraph *depsgraph, Material *mater
 {
   MaterialX::DocumentPtr doc = MaterialX::createDocument();
   if (material->use_nodes) {
-    export_nodegraph(doc, depsgraph, material);
+    export_nodegraph(doc.get(), depsgraph, material);
   }
   else {
-    create_standard_surface(doc, material);
+    create_standard_surface(doc.get(), material);
   }
+  std::string str = MaterialX::writeToXmlString(doc);
+  printf("\nMaterial: %s\n%s\n", material->id.name, str.c_str());
   return doc;
 }
 

source/blender/nodes/shader/materialx/nodes/bsdf_principled.cc

@@ -0,0 +1,145 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "bsdf_principled.h"
+
+#include <BKE_node_runtime.hh>
+
+namespace blender::nodes::materialx {
+
+NodeItem BSDFPrincipledNodeParser::compute()
+{
+  auto enabled = [](NodeItem &val) -> bool {
+    if (val.node) {
+      return true;
+    }
+    if (!val.value) {
+      return false;
+    }
+    if (val.value->isA<float>()) {
+      return val.value->asA<float>() != 0.0f;
+    }
+    if (val.value->isA<MaterialX::Color4>()) {
+      auto c = val.value->asA<MaterialX::Color4>();
+      return c[0] != 0.0f || c[1] != 0.0f || c[2] != 0.0f;
+    }
+    return true;
+  };
+
+  /* Getting required inputs
+   * Note: if some inputs are not needed they won't be taken */
+  NodeItem base_color = get_input_value("Base Color");
+
+  NodeItem subsurface = get_input_value("Subsurface");
+  NodeItem subsurface_radius = empty_value();
+  NodeItem subsurface_color = empty_value();
+  if (enabled(subsurface)) {
+    subsurface_radius = get_input_value("Subsurface Radius");
+    subsurface_color = get_input_value("Subsurface Color");
+  }
+
+  NodeItem metallic = get_input_value("Metallic");
+  NodeItem specular = get_input_value("Specular");
+  // NodeItem specular_tint = get_input_value("Specular Tint");
+  NodeItem roughness = get_input_value("Roughness");
+
+  NodeItem anisotropic = empty_value();
+  NodeItem anisotropic_rotation = empty_value();
+  if (enabled(metallic)) {
+    /* TODO: use Specular Tint input */
+    anisotropic = get_input_value("Anisotropic");
+    if (enabled(anisotropic)) {
+      anisotropic_rotation = get_input_value("Anisotropic Rotation");
+      // anisotropic_rotation = 0.5 - (anisotropic_rotation % 1.0)
+    }
+  }
+
+  NodeItem sheen = get_input_value("Sheen");
+  // sheen_tint = empty_value();
+  // if enabled(sheen):
+  //     sheen_tint = get_input_value("Sheen Tint");
+
+  NodeItem clearcoat = get_input_value("Clearcoat");
+  NodeItem clearcoat_roughness = empty_value();
+  if (enabled(clearcoat)) {
+    clearcoat_roughness = get_input_value("Clearcoat Roughness");
+  }
+
+  NodeItem ior = get_input_value("IOR");
+
+  NodeItem transmission = get_input_value("Transmission");
+  NodeItem transmission_roughness = empty_value();
+  if (enabled(transmission)) {
+    transmission_roughness = get_input_value("Transmission Roughness");
+  }
+
+  NodeItem emission = get_input_value("Emission");
+  NodeItem emission_strength = get_input_value("Emission Strength");
+
+  NodeItem alpha = get_input_value("Alpha");
+  // transparency = 1.0 - alpha
+
+  NodeItem normal = get_input_link("Normal");
+  NodeItem clearcoat_normal = get_input_link("Clearcoat Normal");
+  NodeItem tangent = get_input_link("Tangent");
+
+  /* Creating standard_surface */
+  NodeItem res = create_node("standard_surface", "surfaceshader");
+  res.set_input("base", 1.0, "float");
+  res.set_input("base_color", base_color.to_color3());
+  res.set_input("diffuse_roughness", roughness);
+  res.set_input("normal", normal);
+  res.set_input("tangent", tangent);
+
+  if (enabled(metallic)) {
+    res.set_input("metalness", metallic);
+  }
+
+  if (enabled(specular)) {
+    res.set_input("specular", specular);
+    res.set_input("specular_color", base_color.to_color3());
+    res.set_input("specular_roughness", roughness);
+    res.set_input("specular_IOR", ior);
+    res.set_input("specular_anisotropy", anisotropic);
+    res.set_input("specular_rotation", anisotropic_rotation);
+  }
+
+  if (enabled(transmission)) {
+    res.set_input("transmission", transmission);
+    res.set_input("transmission_color", base_color.to_color3());
+    res.set_input("transmission_extra_roughness", transmission_roughness);
+  }
+
+  if (enabled(subsurface)) {
+    res.set_input("subsurface", subsurface);
+    res.set_input("subsurface_color", subsurface_color);
+    res.set_input("subsurface_radius", subsurface_radius);
+    res.set_input("subsurface_anisotropy", anisotropic);
+  }
+
+  if (enabled(sheen)) {
+    res.set_input("sheen", sheen);
+    res.set_input("sheen_color", base_color.to_color3());
+    res.set_input("sheen_roughness", roughness);
+  }
+
+  if (enabled(clearcoat)) {
+    res.set_input("coat", clearcoat);
+    res.set_input("coat_color", base_color.to_color3());
+    res.set_input("coat_roughness", clearcoat_roughness);
+    res.set_input("coat_IOR", ior);
+    res.set_input("coat_anisotropy", anisotropic);
+    res.set_input("coat_rotation", anisotropic_rotation);
+    res.set_input("coat_normal", clearcoat_normal);
+  }
+
+  if (enabled(emission)) {
+    res.set_input("emission", emission_strength);
+    res.set_input("emission_color", emission);
+  }
+
+  return res;
+}
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/bsdf_principled.h

@@ -0,0 +1,17 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "node_parser.h"
+
+namespace blender::nodes::materialx {
+
+class BSDFPrincipledNodeParser : public NodeParser {
+ public:
+  using NodeParser::NodeParser;
+  NodeItem compute() override;
+};
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/image.cc

@@ -1,45 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#include "node.h"
-#include "image.h"
-
-#include "hydra/image.h"
-
-#include "DEG_depsgraph_query.h"
-
-namespace blender::nodes::materialx {
-
-const MaterialX::Color3 MaterialXTexImageNode::texture_error_color_{1.0, 0.0, 1.0};
-
-MaterialXTexImageNode::MaterialXTexImageNode(MaterialX::DocumentPtr doc,
-                                             const Depsgraph *depsgraph,
-                                             const Material *material,
-                                             const bNode *node)
-    : MaterialXNode(doc, depsgraph, material, node)
-{
-  matx_node = doc->addNode("image", MaterialX::createValidName(node->name), "color3");
-}
-
-MaterialX::NodePtr MaterialXTexImageNode::convert()
-{
-  Image *image = (Image *)node->id;
-  NodeTexImage *tex = static_cast<NodeTexImage *>(node->storage);
-  Scene *scene = DEG_get_input_scene(depsgraph);
-  Main *bmain = DEG_get_bmain(depsgraph);
-  std::string image_path;
-  /* TODO: What if Blender built without Hydra? Also io::hydra::cache_or_get_image_file contain
-   * pretty general code, so could be moved from bf_usd project. */
-#ifdef WITH_HYDRA
-  image_path = io::hydra::cache_or_get_image_file(bmain, scene, image, &tex->iuser);
-#endif
-  MaterialX::NodePtr uv_node = doc->addNode("texcoord", MaterialX::EMPTY_STRING, "vector2");
-
-  matx_node->addInput("file", "filename")->setValue(image_path);
-  matx_node->addInput("texcoord", "vector2")->setNodeName(uv_node->getName());
-
-  return matx_node;
-}
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/image.h

@@ -1,24 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#pragma once
-
-#include "node.h"
-
-namespace blender::nodes::materialx {
-
-class MaterialXTexImageNode : public MaterialXNode {
- protected:
-  /* Following Cycles color for wrong Texture nodes. */
-  static const MaterialX::Color3 texture_error_color_;
-
- public:
-  MaterialXTexImageNode(MaterialX::DocumentPtr doc,
-                        const Depsgraph *depsgraph,
-                        const Material *material,
-                        const bNode *node);
-  MaterialX::NodePtr convert() override;
-};
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/material_output.cc

@@ -1,35 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#include "material_output.h"
-#include "principled_bsdf.h"
-
-namespace blender::nodes::materialx {
-
-MaterialXMaterialOutputNode::MaterialXMaterialOutputNode(MaterialX::DocumentPtr doc,
-                                                         const Depsgraph *depsgraph,
-                                                         const Material *material,
-                                                         const bNode *node)
-    : MaterialXNode(doc, depsgraph, material, node)
-{
-  matx_node = doc->addNode("surfacematerial", MaterialX::createValidName(node->name), "material");
-}
-
-MaterialX::NodePtr MaterialXMaterialOutputNode::convert()
-{
-  LISTBASE_FOREACH (const bNodeSocket *, sock, &node->inputs) {
-    if (!sock->link) {
-      continue;
-    }
-    if (STREQ(sock->name, "Surface")) {
-      const bNode *inode = sock->link->fromnode;
-      MaterialXPrincipledBSDFNode surface_node(doc, depsgraph, material, inode);
-      surface_node.convert();
-      matx_node->addInput("surfaceshader", "surfaceshader")->setNodeName(inode->name);
-    }
-  }
-  return matx_node;
-}
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/material_output.h

@@ -1,20 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#pragma once
-
-#include "node.h"
-
-namespace blender::nodes::materialx {
-
-class MaterialXMaterialOutputNode : public MaterialXNode {
- public:
-  MaterialXMaterialOutputNode(MaterialX::DocumentPtr doc,
-                              const Depsgraph *depsgraph,
-                              const Material *material,
-                              const bNode *node);
-  MaterialX::NodePtr convert() override;
-};
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/node.cc

@@ -1,17 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#include "node.h"
-
-namespace blender::nodes::materialx {
-
-MaterialXNode::MaterialXNode(MaterialX::DocumentPtr doc,
-                             const Depsgraph *depsgraph,
-                             const Material *material,
-                             const bNode *node)
-    : depsgraph(depsgraph), material(material), node(node), doc(doc)
-{
-}
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/node.h

@@ -1,33 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#pragma once
-
-#include <MaterialXCore/Document.h>
-
-#include "DEG_depsgraph.h"
-#include "DNA_material_types.h"
-#include "DNA_node_types.h"
-
-namespace blender::nodes::materialx {
-
-class MaterialXNode {
- public:
-  const Depsgraph *depsgraph = nullptr;
-  const Material *material = nullptr;
-  const bNode *node = nullptr;
-  MaterialX::NodePtr matx_node;
-  MaterialX::DocumentPtr doc;
-
- public:
-  MaterialXNode(MaterialX::DocumentPtr doc,
-                const Depsgraph *depsgraph,
-                const Material *material,
-                const bNode *node);
-  virtual ~MaterialXNode() = default;
-
-  virtual MaterialX::NodePtr convert() = 0;
-};
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/node_parser.cc

@@ -0,0 +1,180 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "node_parser.h"
+
+#include "bsdf_principled.h"
+#include "tex_image.h"
+
+#include <BKE_node_runtime.hh>
+
+namespace blender::nodes::materialx {
+
+NodeItem::NodeItem(MaterialX::GraphElement *graph) : graph_(graph) {}
+
+void NodeItem::set_input(const std::string &name, const NodeItem &item)
+{
+  if (item.value) {
+    set_input(name, item.value);
+  }
+  else if (item.node) {
+    set_input(name, item.node);
+  }
+}
+
+void NodeItem::set_input(const std::string &name, const MaterialX::ValuePtr value)
+{
+  if (value->isA<float>()) {
+    set_input(name, value->asA<float>(), "float");
+  }
+  else if (value->isA<MaterialX::Vector3>()) {
+    set_input(name, value->asA<MaterialX::Vector3>(), "vector3");
+  }
+  else if (value->isA<MaterialX::Vector4>()) {
+    set_input(name, value->asA<MaterialX::Vector4>(), "vector4");
+  }
+  else if (value->isA<MaterialX::Color3>()) {
+    set_input(name, value->asA<MaterialX::Color3>(), "color3");
+  }
+  else if (value->isA<MaterialX::Color4>()) {
+    set_input(name, value->asA<MaterialX::Color4>(), "color4");
+  }
+  else {
+    BLI_assert_unreachable();
+  }
+}
+
+void NodeItem::set_input(const std::string &name, const MaterialX::NodePtr node)
+{
+  this->node->setConnectedNode(name, node);
+}
+
+NodeItem::operator bool() const
+{
+  return value || node;
+}
+
+NodeItem NodeItem::to_color3()
+{
+  NodeItem res(graph_);
+  if (value) {
+    if (value->isA<float>()) {
+      float v = value->asA<float>();
+      res.value = MaterialX::Value::createValue<MaterialX::Color3>(MaterialX::Color3(v, v, v));
+    }
+    else if (value->isA<MaterialX::Color3>()) {
+      res.value = value;
+    }
+    else if (value->isA<MaterialX::Color4>()) {
+      auto c = value->asA<MaterialX::Color4>();
+      res.value = MaterialX::Value::createValue<MaterialX::Color3>(
+          MaterialX::Color3(c[0], c[1], c[2]));
+    }
+  }
+  else if (node) {
+    res.node = node;
+  }
+  return res;
+}
+
+NodeParser::NodeParser(MaterialX::GraphElement *graph,
+                       const Depsgraph *depsgraph,
+                       const Material *material,
+                       const bNode *node)
+    : graph(graph), depsgraph(depsgraph), material(material), node(node)
+{
+}
+
+NodeItem NodeParser::create_node(const std::string &mx_category,
+                                 const std::string &mx_type,
+                                 bool accessory)
+{
+  NodeItem res = empty_value();
+  res.node = graph->addNode(mx_category,
+                            accessory ? MaterialX::EMPTY_STRING :
+                                        MaterialX::createValidName(node->name),
+                            mx_type);
+  return res;
+}
+
+NodeItem NodeParser::get_input_default(const std::string &name)
+{
+  NodeItem res = empty_value();
+
+  const bNodeSocket &socket = node->input_by_identifier(name);
+  switch (socket.type) {
+    case SOCK_FLOAT: {
+      float v = socket.default_value_typed<bNodeSocketValueFloat>()->value;
+      res.value = MaterialX::Value::createValue<float>(v);
+    } break;
+    case SOCK_VECTOR: {
+      const float *v = socket.default_value_typed<bNodeSocketValueVector>()->value;
+      res.value = MaterialX::Value::createValue<MaterialX::Vector3>(
+          MaterialX::Vector3(v[0], v[1], v[2]));
+    } break;
+    case SOCK_RGBA: {
+      const float *v = socket.default_value_typed<bNodeSocketValueRGBA>()->value;
+      res.value = MaterialX::Value::createValue<MaterialX::Color4>(
+          MaterialX::Color4(v[0], v[1], v[2], v[3]));
+    } break;
+    default: {
+      // TODO log warn
+    }
+  }
+  return res;
+}
+
+NodeItem NodeParser::get_input_link(const std::string &name)
+{
+  NodeItem res = empty_value();
+
+  const bNodeLink *link = node->input_by_identifier(name).link;
+  if (!(link && link->is_used())) {
+    return res;
+  }
+
+  const bNode *in_node = link->fromnode;
+
+  /* Passing NODE_REROUTE nodes */
+  while (in_node->type == NODE_REROUTE) {
+    link = in_node->input_socket(0).link;
+    if (!(link && link->is_used())) {
+      return res;
+    }
+    in_node = link->fromnode;
+  }
+
+  /* Getting required NodeParser object */
+  std::unique_ptr<NodeParser> parser;
+  switch (in_node->type) {
+    case SH_NODE_BSDF_PRINCIPLED:
+      parser = std::make_unique<BSDFPrincipledNodeParser>(graph, depsgraph, material, in_node);
+      break;
+    case SH_NODE_TEX_IMAGE:
+      parser = std::make_unique<TexImageNodeParser>(graph, depsgraph, material, in_node);
+      break;
+    default:
+      // TODO: warning log
+      return res;
+  }
+
+  res = parser->compute();
+  return res;
+}
+
+NodeItem NodeParser::get_input_value(const std::string &name)
+{
+  NodeItem res = get_input_link(name);
+  if (!res) {
+    res = get_input_default(name);
+  }
+  return res;
+}
+
+NodeItem NodeParser::empty_value()
+{
+  return NodeItem(graph);
+}
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/node_parser.h

@@ -0,0 +1,70 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include <MaterialXCore/Document.h>
+
+#include "DEG_depsgraph.h"
+#include "DNA_material_types.h"
+#include "DNA_node_types.h"
+
+namespace blender::nodes::materialx {
+
+class NodeItem {
+ public:
+  MaterialX::ValuePtr value;
+  MaterialX::NodePtr node;
+
+ private:
+  MaterialX::GraphElement *graph_;
+
+ public:
+  NodeItem(MaterialX::GraphElement *graph);
+  ~NodeItem() = default;
+
+  template<class T>
+  void set_input(const std::string &name, const T &value, const std::string &mx_type);
+  void set_input(const std::string &name, const NodeItem &item);
+  void set_input(const std::string &name, const MaterialX::ValuePtr value);
+  void set_input(const std::string &name, const MaterialX::NodePtr node);
+
+  operator bool() const;
+
+  NodeItem to_color3();
+};
+
+template<class T>
+void NodeItem::set_input(const std::string &name, const T &value, const std::string &mx_type)
+{
+  node->setInputValue(name, value, mx_type);
+}
+
+class NodeParser {
+ public:
+  MaterialX::GraphElement *graph;
+  const Depsgraph *depsgraph;
+  const Material *material;
+  const bNode *node;
+
+ public:
+  NodeParser(MaterialX::GraphElement *graph,
+             const Depsgraph *depsgraph,
+             const Material *material,
+             const bNode *node);
+  virtual ~NodeParser() = default;
+
+  virtual NodeItem compute() = 0;
+
+ protected:
+  NodeItem create_node(const std::string &mx_category,
+                       const std::string &mx_type,
+                       bool accessory = false);
+  NodeItem get_input_default(const std::string &name);
+  NodeItem get_input_link(const std::string &name);
+  NodeItem get_input_value(const std::string &name);
+  NodeItem empty_value();
+};
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/output_material.cc

@@ -0,0 +1,20 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "output_material.h"
+
+namespace blender::nodes::materialx {
+
+NodeItem OutputMaterialNodeParser::compute()
+{
+  NodeItem node = empty_value();
+  NodeItem surface = get_input_link("Surface");
+  if (surface) {
+    node = create_node("surfacematerial", "material");
+    node.set_input("surfaceshader", surface);
+  }
+  return node;
+}
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/output_material.h

@@ -0,0 +1,17 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "node_parser.h"
+
+namespace blender::nodes::materialx {
+
+class OutputMaterialNodeParser : public NodeParser {
+ public:
+  using NodeParser::NodeParser;
+  NodeItem compute() override;
+};
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/principled_bsdf.cc

@@ -1,126 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#include "principled_bsdf.h"
-
-#include <BKE_node_runtime.hh>
-
-namespace blender::nodes::materialx {
-
-const MaterialX::Color3 MaterialXPrincipledBSDFNode::default_white_color_{1.0, 1.0, 1.0};
-
-MaterialXPrincipledBSDFNode::MaterialXPrincipledBSDFNode(MaterialX::DocumentPtr doc,
-                                                         const Depsgraph *depsgraph,
-                                                         const Material *material,
-                                                         const bNode *node)
-    : MaterialXNode(doc, depsgraph, material, node)
-{
-  matx_node = doc->addNode(
-      "standard_surface", MaterialX::createValidName(node->name), "surfaceshader");
-}
-
-MaterialX::NodePtr MaterialXPrincipledBSDFNode::convert()
-{
-#pragma region get inputs
-  const float *base_color =
-      node->input_by_identifier("Base Color").default_value_typed<bNodeSocketValueRGBA>()->value;
-  const float subsurface =
-      node->input_by_identifier("Subsurface").default_value_typed<bNodeSocketValueFloat>()->value;
-
-  const float *subsurface_radius = node->input_by_identifier("Subsurface Radius")
-                                       .default_value_typed<bNodeSocketValueVector>()
-                                       ->value;
-  const float *subsurface_color = node->input_by_identifier("Subsurface Color")
-                                      .default_value_typed<bNodeSocketValueRGBA>()
-                                      ->value;
-  const float metallic =
-      node->input_by_identifier("Metallic").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float specular =
-      node->input_by_identifier("Specular").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float roughness =
-      node->input_by_identifier("Roughness").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float anisotropic =
-      node->input_by_identifier("Anisotropic").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float anisotropic_rot = node->input_by_identifier("Anisotropic Rotation")
-                                    .default_value_typed<bNodeSocketValueFloat>()
-                                    ->value;
-  const float sheen =
-      node->input_by_identifier("Sheen").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float clearcoat =
-      node->input_by_identifier("Clearcoat").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float clearcoat_roughness = node->input_by_identifier("Clearcoat Roughness")
-                                        .default_value_typed<bNodeSocketValueFloat>()
-                                        ->value;
-  const float IOR =
-      node->input_by_identifier("IOR").default_value_typed<bNodeSocketValueFloat>()->value;
-  const float transmission = node->input_by_identifier("Transmission")
-                                 .default_value_typed<bNodeSocketValueFloat>()
-                                 ->value;
-  const float *emission =
-      node->input_by_identifier("Emission").default_value_typed<bNodeSocketValueRGBA>()->value;
-  const float emission_str = node->input_by_identifier("Emission Strength")
-                                 .default_value_typed<bNodeSocketValueFloat>()
-                                 ->value;
-  const float *normal =
-      node->input_by_identifier("Normal").default_value_typed<bNodeSocketValueVector>()->value;
-  const float *clearcoat_normal = node->input_by_identifier("Clearcoat Normal")
-                                      .default_value_typed<bNodeSocketValueVector>()
-                                      ->value;
-  const float *tangent =
-      node->input_by_identifier("Tangent").default_value_typed<bNodeSocketValueVector>()->value;
-#pragma endregion get inputs
-
-#pragma region set inputs
-  matx_node->addInput("base", "float")->setValue(1.0);
-  matx_node->addInput("base_color", "color3")
-      ->setValue(MaterialX::Color3(base_color[0], base_color[1], base_color[2]));
-  matx_node->addInput("diffuse_roughness", "float")->setValue(roughness);
-  matx_node->addInput("normal", "vector3")
-      ->setValue(MaterialX::Vector3(normal[0], normal[1], normal[2]));
-  matx_node->addInput("tangent", "vector3")
-      ->setValue(MaterialX::Vector3(tangent[0], tangent[1], tangent[2]));
-
-  matx_node->addInput("metalness", "float")->setValue(metallic);
-
-  matx_node->addInput("specular", "float")->setValue(specular);
-  matx_node->addInput("specular_color", "color3")->setValue(default_white_color_);
-  matx_node->addInput("specular_roughness", "float")->setValue(roughness);
-  matx_node->addInput("specular_IOR", "float")->setValue(IOR);
-  matx_node->addInput("specular_anisotropy", "float")->setValue(anisotropic);
-  matx_node->addInput("specular_rotation", "float")->setValue(anisotropic_rot);
-
-  matx_node->addInput("transmission", "float")->setValue(transmission);
-  matx_node->addInput("transmission_color", "color3")->setValue(default_white_color_);
-  matx_node->addInput("transmission_extra_roughness", "float")->setValue(roughness);
-
-  matx_node->addInput("subsurface", "float")->setValue(subsurface);
-  matx_node->addInput("subsurface_color", "color3")
-      ->setValue(MaterialX::Color3(subsurface_color[0], subsurface_color[1], subsurface_color[2]));
-  matx_node->addInput("subsurface_radius", "color3")
-      ->setValue(
-          MaterialX::Color3(subsurface_radius[0], subsurface_radius[1], subsurface_radius[2]));
-  matx_node->addInput("subsurface_anisotropy", "float")->setValue(anisotropic);
-
-  matx_node->addInput("sheen", "float")->setValue(sheen);
-  matx_node->addInput("sheen_color", "color3")->setValue(default_white_color_);
-  matx_node->addInput("sheen_roughness", "float")->setValue(roughness);
-
-  matx_node->addInput("coat", "float")->setValue(clearcoat);
-  matx_node->addInput("coat_color", "color3")->setValue(default_white_color_);
-  matx_node->addInput("coat_roughness", "float")->setValue(clearcoat_roughness);
-  matx_node->addInput("coat_IOR", "float")->setValue(IOR);
-  matx_node->addInput("coat_anisotropy", "float")->setValue(anisotropic);
-  matx_node->addInput("coat_rotation", "float")->setValue(anisotropic_rot);
-  matx_node->addInput("coat_normal", "vector3")
-      ->setValue(
-          MaterialX::Vector3(clearcoat_normal[0], clearcoat_normal[1], clearcoat_normal[2]));
-
-  matx_node->addInput("emission", "float")->setValue(emission_str);
-  matx_node->addInput("emission_color", "color3")
-      ->setValue(MaterialX::Color3(emission[0], emission[1], emission[2]));
-#pragma endregion set inputs
-  return matx_node;
-}
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/principled_bsdf.h

@@ -1,23 +0,0 @@
-/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
- *
- * SPDX-License-Identifier: GPL-2.0-or-later */
-
-#pragma once
-
-#include "node.h"
-
-namespace blender::nodes::materialx {
-
-class MaterialXPrincipledBSDFNode : public MaterialXNode {
- protected:
-  static const MaterialX::Color3 default_white_color_;
-
- public:
-  MaterialXPrincipledBSDFNode(MaterialX::DocumentPtr doc,
-                              const Depsgraph *depsgraph,
-                              const Material *material,
-                              const bNode *node);
-  MaterialX::NodePtr convert() override;
-};
-
-}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/tex_image.cc

@@ -0,0 +1,34 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "tex_image.h"
+#include "node_parser.h"
+
+#include "hydra/image.h"
+
+#include "DEG_depsgraph_query.h"
+
+namespace blender::nodes::materialx {
+
+NodeItem TexImageNodeParser::compute()
+{
+  Image *image = (Image *)node->id;
+  NodeTexImage *tex = static_cast<NodeTexImage *>(node->storage);
+  Scene *scene = DEG_get_input_scene(depsgraph);
+  Main *bmain = DEG_get_bmain(depsgraph);
+  std::string image_path;
+  /* TODO: What if Blender built without Hydra? Also io::hydra::cache_or_get_image_file contain
+   * pretty general code, so could be moved from bf_usd project. */
+#ifdef WITH_HYDRA
+  image_path = io::hydra::cache_or_get_image_file(bmain, scene, image, &tex->iuser);
+#endif
+
+  NodeItem texcoord = create_node("texcoord", "vector2", true);
+  NodeItem res = create_node("image", "color3");
+  res.set_input("file", image_path, "filename");
+  res.set_input("texcoord", texcoord);
+  return res;
+}
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/tex_image.h

@@ -0,0 +1,17 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "node_parser.h"
+
+namespace blender::nodes::materialx {
+
+class TexImageNodeParser : public NodeParser {
+ public:
+  using NodeParser::NodeParser;
+  NodeItem compute() override;
+};
+
+}  // namespace blender::nodes::materialx

source/blender/render/hydra/engine.cc

@@ -89,6 +89,7 @@ void Engine::sync(Depsgraph *depsgraph, bContext *context)
       pxr::SdfPath scene_path = pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene");
       hydra_scene_delegate_ = std::make_unique<io::hydra::HydraSceneDelegate>(render_index_.get(),
                                                                               scene_path);
+      hydra_scene_delegate_->use_materialx = bl_engine_->type->flag & RE_USE_MATERIALX;
     }
     hydra_scene_delegate_->populate(depsgraph, context ? CTX_wm_view3d(context) : nullptr);
   }